Bengt Glimelius, Jesper Ryg, Pia Österlund, Eva Hofsli, Gabor Liposits, Camilla Qvortrup, Sören Möller, Per Pfeiffer, Henrik Eshøj, Laurids Østergaard Poulsen, Halfdan Sorbye, Stine Braendegaard Winther, Åke Berglund, Carl-Henrik Shah, Hella Skuladottir, Tampere University, Department of Oncology, Clinical Medicine, HUS Comprehensive Cancer Center, Doctoral Programme in Biomedicine, and Clinicum
Quality of life data from randomized trials are lacking in older patients with metastatic colorectal cancer (mCRC). In the randomized NORDIC9-study, reduced-dose S1+oxaliplatin (SOx) showed superior efficacy compared to full-dose S1 monotherapy. We hypothesized that treatment with SOx does not result in inferior quality of life. Patients with mCRC aged ≥ 70 years and that were not a candidate for standard combination chemotherapy were included and randomly assigned to receive either S1 or SOx. The EORTC QLQ-C30 questionnaire was completed at baseline, after 9, and 18 weeks. The primary endpoint was global Quality of Life (QoL) at 9 weeks. For statistical analysis, a non-inferiority design was chosen applying linear mixed effects models for repeated measurements. The results were interpreted according to statistical significance and anchor-based, clinically relevant between-group minimally important differences (MID). A total of 160 patients aged (median (Interquartile range (IQR))) 78 years (76–81) were included. The QLQ-C30 questionnaire was completed by 150, 100, and 60 patients at baseline, at 9, and 18 weeks, respectively. The difference at 9 weeks in global QoL was 6.85 (95%CI -1.94, 15.65) and 7.37 (0.70, 14.05) in the physical functioning domain in favor of SOx exceeding the threshold for MID. At 18 weeks, the between-group MID in physical functioning was preserved. Dose-reduced combination chemotherapy may be recommended in vulnerable older patients with mCRC, rather than full-dose monotherapy.